Monday, December 17, 2012

Since I am a little pressed in time, I won't beat around the bush, but rather get to the meat of the matter of this Nutrition Quickie, right away... well, actually today's nutrition quickie has no item on meats, but is has one Dendrobium, which is actually rather a supplement - be that as it may, here you go:

Since you (hopefully ;-) haven't swallowed a bomb colorimeter, it's actually no wonder that your body can only access 75% and 95% of the energy this little oven can squeeze out of almonds and pistachios. If you went with the Atwood factor (which says fat = 9kcal/g) and simply added fats, proteins and carbs the discrepancy for almonds would even increase to ~35% (Nowotny. 2012)

Almonds deliver 25% less calories that the nutritional label will tell you (Gebauer. 2012) -- At the FASEB meeting in April 2012, already, scientists from nowhere else than the mighty USDA, respectively the Beltsville Human Nutrition Research Center of the USDA presented the results of a human study that clearly shows that our tummies cannot squeeze out more than 75% of the nutrients a bomb calorimeter does. Nutrition Quickie: 25% Less Kcal in Almonds Than Label Says.

The caloric value on both food labels and respective nutrient tables is thus off 25% too high. And the corrected energy content per 100g of almonds is 456kcal/100g not 575kcal/100g (nutritiondata.com), or even higher values you will find when you google "almonds kcal" - I am curious if at least the nutrition labes will ever be updated.

A similar but less pronounced mismatch has been found for pistachios by the same researchers earlier this year, already. According to a paper published in the January edition of the British Journal of Nutrition (Bear. 2012), the actual energy content of these heart healthy nuts 565kcal/100g, which is ~5% less than the currently established value.

Bioavailability of pistachio polyphenols, xanthophylls, and tocopherols is very high - until you put them into a muffin (Mandalari. 2013) -- Bioavailability, i.e. the ratio of the total amount of a certain molecule that's in the food we eat in intact or at least active form in our bloodstream, can be a real issue for many of the good things the spectral analyzer of brainy scientists detects in our foodstuff.

In the upcoming January issue of Nutrition a group of researchers from the UK and Italy report the results of an investigation into the bioavailability of polyphenols, xanthophylls (lutein), and tocopherols (among them the rare gamma-variety) from raw pistachios, roasted salted pistachios, and muffins made with raw
pistachios. You can see the original polyphenol, xanthophyll and tocopherol (mind the 90% gamma-tocopherol content, which has better chemoprotective effects than alpha-tocopherol; see "Vitamin(S!) E" post from 2011) content in table 1.

Interestingly enough the availability of the tocopherols was almost identical for all three tested forms (raw, roasted, in muffins) and even the muffin reduced only the bioaccessability of protocatechuic acid (78%) and luteolin (36%), the rest of the phenols achieved the same ~90% Madalari et al. observed for the raw and roasted + salted pistachios in their million dollar model of the human digestive tract (click here for an article about this "artificial gut")

When the gut "tastes" phenylalanine (PHE), leucine (LEU), glutamate (GLUT) and tryptophane (TRP), satiety ensues (Daly. 2012) -- In their most recent paper Christin Daly et al. report on the cholecystokinin (CCK) release in the gut. According to the scientists from the University of Liverpool (UK) and the Kyushu University (Japan), the effect is mediated by interactions with the gastrointestinal bitter taste receptors. Since CCK inhibits food intake and reduces appetite, this provides another mechanistic explanation for the satiety promoting effects of high protein intakes. The effects was observed only for the L- and not the D-amino acids.

Interestingly, the beneficial effects of PHE, LEU and GLUT on CCK (but not the TRP-stimulated CCK secretion) were blunted in the presence of gurmarin. "Gurmarin?" Yeah, that's the rodent specific sweet taste inhibitor in Gymnema sylvestre (note gurmarin does not work in humans; cf. Sigoillot. 2012), which is sold as an anti-diabetes supplement. Inosine, on the other hand increased the CCK release n response to all of the amino acids.

How significant that is specifically for those who have a problem keeping their ravenous appetite in check is however questionable. After all the satiety response to CCK has been shown to be disturbed (at least in rodents; cf. Balaskó. 2012)

Table 2: Number of mice protected by the administered drug in the MES test (Talevi. 2012)

Acesulfame potassium, cyclamate and saccharin are potential anti-convulsants (Talevi. 2012) -- It may sound counter-intuitive in view of all the bad stuff you have probably heard about artificial sweeteners, but it is their particular molecular structure and similarities between the T1R3 sweet taste receptor they are supposed to bind to ant several metabotropic glutamate receptors from different species that is probably behind the anticonvulsant effects a group of researchers from the Department of Biological Sciences at the Faculty of Exact Sciences of the National University of La Plata (UNLP) in Buenos Aires, Argentina.

The overall effect size the scientists observed in their rodent model (see table 2) is yet far from earth shattering and generally more pronounced if the sweeteners had been ingested 4h instead of just 20 min before a Maximal Electroshock Seizure (MES) test. Whether this makes them worth "supplementing" is however more than questionable.

Putting things into perspective: While the DPPH radical
scavenging activity is not a really good measure of the in-vivo
anti-oxidant potency of a given molecule it may yet still be worth
mentioning that the one of Dendrobium (IC50 = 29.6 μg/mL) is more than 80% lower than that Areca catechuvar. Cinnamon cassia, Paeonia suffruticosa and Alpinia officinarum extracts which share IC50 values <6µg/mL (Lee. 2003). In other words, you need 80% more Dendrobium than cinnamon, for example, to neutralize the same amount H2O2 radicals.

Dendrobium extract ameliorates renal fat accumulation, hyperglycemia and hyperlipidemia in rodents on "high fat" diet (Lee. 20012) -- While I cannot say if this is the same Dendrobium extract that's used in a pre-workout supplement that's "all the craze", these days, I can tell you that a group of researchers just published a paper on the renoprotective, hypoglycemic and hypolipidemic effects of an extract from Dendrobium moniliforme (a cursory search revealed that even within this genus of orchids there are at least 90 sub-types ranging from Aochidori to Yuten).

Lee et al. administered the methanolic extract at dosages of 200mg/kg (HED ~16mg/kg) for nine weeks and reduced the elevated serum glucose, total cholesterol concentration and renal lipid accumulation in the HFD-fed mice. It also ameliorated renal dysfunction biomarkers including serum creatinine and renal collagen IV deposition. So that the scientists conclude that methanolic extracts from Dendrobium moniliforme exhibit pleiotropic effects on obesity induced parameters and exert renoprotective effect in HFD-fed mice.

That's it for today, unless you are are interested in one of the following facebook news:

Endocannabinoids increase, leptin decreases a
"sweet tooth" - And you can take this almost literally, since they do
actually modulate sweet taste receptor sensitivity (read more)

There are actually a couple more and they will "proliferate" *rofl* even before the next official SuppVersity post will be published. Reason enough to check by from time to time, or simply "like" the SuppVersity on Facebook in order to keep up with the news.

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The information provided on this website is for informational purposes only. It is by no means intended as professional medical advice. Do not use any of the agents or freely available dietary supplements mentioned on this website without further consultation with your medical practitioner.